AB0940 TITLE: CHOICE OF BDMARD AFTER TNFI: DOES IT MATTER IN THE TREATMENT OF SPONDYLOARTHRITIS?
Authors: G. D. İşbilir, R. C. Kardaş, D. Yildirim, B. Özkiziltaş, I. Vasi, R. Duran, H. Karadeniz, A. Avanoglu Guler, A. Erden, H. Küçük, A. Tufan, B. Göker, M. A. Ozturk
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Following the failure of initial biological treatment in spondyloarthritis, switching to an alternative biological drug is possible. However, the data regarding the choice of the drug is limited. ASAS/EULAR guideline on axial spondyloarthritis does not make a distinction between TNFi, IL-17i or JAKi, with certain precautions regarding JAKi [1]. On the other hand, ACR/SAA/SPARTAN guideline recommends IL-17i over a different TNFi in primary failure, based on the assumption that TNF is not the key inflammatory mediator in these patients [2]. <h3>Objectives</h3> Our main objective was to compare and contrast the clinical and laboratory features of the patients who received either a TNFi or IL-17i following the failure of the initial biologic treatment in our cohort of spondyloarthritis patients. <h3>Methods</h3> Spondyloarthritis patients followed in our institution between 2014 and 2022 who received a secondary bDMARD following primary or secondary biologic failure were included in our study. ASAS criteria were used to classify patients as having axial or peripheral SpA. Failure was defined as lack of clinical improvement following at least 12 weeks of therapy. Demographic, clinical, laboratory and radiological features of the patients, along with clinical and laboratory response following the second line bDMARD treatment were recorded. <h3>Results</h3> 90 patients were included in our study. 51% were female (N=46), mean age at diagnosis was 35 (SD: 11.9, %95 CI: 32.5–37.6), median duration of disease was 9 years (IQR: 10, minimum: 2 years, maximum: 38 years). 76% (N=68) of patients were classified as axial SpA, remaining 22 were classsifed as peripheral SpA. 68% (N=58) were HLA-B27 positive. Median ASDAS-CRP before the intial bDMARD was 3.7 (IQR: 1.3, min-max: 2.6–5.9). Adalimumab was the most used initial TNFi (48%, N=43). Most common reason of treatment switch was secondary failure (51%, N=41), followed by primary failure (25%, N=20) and side effects (19%, N=15). Following initial treatment failure, 30% of patients (N=27) were switched to a drug with an alternative pathway, with most of them being secukinumab (N=22). Median ASDAS-CRP after initial treatment failure was 3.8 (IQR: 1.0, min-max: 2.5–6.0). There was no difference in type of spondylarthritis, HLA-B27 positivity, ASDAS-CRP score and choice of bDMARD between primary and secondary failure groups. 24% of patients (N=22) achieved clinical remision in the secondary line of bDMARD treatment. The rate of clinical remission was 5% for TNFi and 75% for IL-17i (P&lt;0.001). Duration of disease was shorter for responders (median 4 years vs. 11 years, P=0,03). Gender, HLA-B27 status, presence of enthesitis, dactylitis, uveitis, skin involvement, gastrointestinal involvement and initial ASDAS-CRP score did not differ between responders and non-responders (Table 1). <h3>Conclusion</h3> The rate of remission for IL-17i was significantly higher than TNFi following the failure of initial bDMARD failure. There was no difference between clinical and laboratory features of responders and non-responders, except for duration of disease. These findings suggest using an alternative pathway in case of TNFi failure may be preferable. <h3>References</h3> [1]Ramiro S, Nikiphorou E, Sepriano A, <i>et al.</i> ASAS-EULAR recommendations for the management of axial spondyloarthritis: 2022 update. <i>Ann Rheum Dis</i> 2023;<b>82</b>:19–34. [2]Ward MM, Deodhar A, Gensler LS, <i>et al.</i> 2019 Update of the ACR/SAA/SPARTAN Recommendations for the Treatment of Ankylosing Spondylitis and Nonradiographic Axial Spondyloarthritis. <i>Arthritis Rheumatol Hoboken NJ</i> 2019;<b>71</b>:1599–613. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None Declared.